In the current information and communication society, demands for a semiconductor device that may more rapidly process more information so as to perform a two-way communication by variously using text, voices, images, and the like are increased. However, a volatile memory of current storage devices has reached limitations in its growth, and accordingly the next generation memory to replace this volatile memory is required to be developed. Development of a non-volatile memory device enabling ultra-large-scale integration required for high capacity information storage is in high demand.
A resistive random access memory device (ReRAM) among the non-volatile memories is a non-volatile memory in which electric resistance of materials is changed by means of an external voltage and the change in the electric resistance is used to signify On/Off. The ReRAM may act as one of next generation non-volatile memory devices for replacing current memory devices in markets mainly occupied by Dynamic RAMs (DRAMs) and flash memories. Accordingly, the ReRAM is highly expected to implement high integration because of a relatively simple structure in comparison with other types of non-volatile memories.
The ReRAM may be embodied to have various materials and structures, however, binary oxides, perovskite oxides containing manganese (Mn), and perovskite oxides with a small amount of doped metal are generally used. Development of the ReRAM using oxide-based materials may be expected to increase a degree of integration of the non-volatile memory device, thereby finding a new memory device market and rapidly improving performance of various electronic devices.
However, oxides used in the conventional ReRAM are of a thin film type formed by physical vapor deposition (PVD), chemical vapor deposition (CVD), and other sputtering methods. Due to complexity of the entire process and a requirement for a high vacuum condition, the conventional process for manufacturing these oxide thin films have problems in that the manufacturing cost is high, reproducibility of the process and the ultra-large-scale integration are difficult to be realized.